Autopilot Operation: Following A Track - Auto/Alc Mode; Power Steer - ComNav Commander P2 Installation & Operation Manual

ComNav Commander P2 Installation & Operation
Autopilot Operation: Following a Track – AUTO/ALC Mode
Some ComNav autopilots provide another way to keep your boat on a specific Track:
Automatic Leeway Correction.
This feature – an element of ComNav's unique Intelligent Steering Technology (also called
IST) – can be turned on in AUTO mode.
ALC is similar to NAV mode, in that it uses NMEA 0183 Latitude/Longitude data to sense if
the boat is following the desired Track.
Unlike NAV mode, however, a ComNav autopilot with the ALC feature only needs
Latitude/Longitude data in AUTO/ALC mode. It does not need Cross-Track error data from
the external Navigation System, nor that there be any waypoints set in the system. The IST
feature calculates the Cross-Track error on its own, using the desired heading active at the
point in time when AUTO/ALC mode is first engaged.

Power Steer

Most ComNav autopilots have a POWER STEER mode, which provides a way for the user to
directly control the rudder. Basically, the autopilot acts as a sort of "electronic steering
wheel", allowing the operator to steer the vessel manually, in a similar way as when using a
standard manual steering wheel or tiller, but from the autopilot's Control Head or any remote
controls it is equipped with.
Steering, when using the autopilot in this mode, is done with two buttons and/or a knob on
the Control Head. One button, and/or a clockwise turn of the knob, will move the rudder to
Starboard; the other button, and/or a counter-clockwise turn of the knob, will move the rudder
to Port.
Using the buttons/knob, the rudder can be placed in any desired position where it will remain.
This feature is useful when docking or manoeuvring, because the person steering the vessel
can take their hands off the controls between rudder movements.
Document PN 29010074 V3.1
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How Autopilots Work